Data study · Niche schema types AI answers can read
87.6% of Inner Pages on Top-1M Forum Sites Carry No DiscussionForumPosting or QAPage Markup
On sites running forum software, 3,233 of 3,692 crawled inner pages (87.6%) have neither forum nor Q&A markup in October 2026. Coverage has crept up from 9.4% in 2023 while the number of forum sites in the top 1M halved.
Analysis of 3,692 inner pages on 3,910 top-1M sites running forum software · HTTP Archive, October 2026, with trend back to 2023
Key findings
- 1
87.6% of crawled inner pages on forum sites (3,233 of 3,692) carry neither DiscussionForumPosting nor QAPage markup.
- 2
Coverage rose from 9.4% of inner pages in 2023 (733 of 7,799) to 12.4% in 2026 (459 of 3,692).
- 3
The number of top-1M sites running detected forum software fell from 7,952 in 2023 to 3,910 in 2026 (-50.8%).
- 4
XenForo accounts for 74.7% of forum-marked inner pages; 23.0% of its crawled inner pages carry the markup.
- 5
When DiscussionForumPosting is present, author (99.5%) and datePublished (98.2%) are nearly always included, but text appears on only 50.3% of pages and comment on 16.6%.
Summary
Picture a long-running forum for vintage motorcycle owners with 20 years of threads on carburetor tuning. When someone asks an AI assistant how to fix a specific model's idle problem, that thread might hold the best answer on the web. Forum markup tells machines what the thread is, who posted it, when, and what replies it has.
Google added DiscussionForumPosting support in late 2023 to help it understand forum content, and QAPage covers question-and-answer threads. AI answers lean heavily on community discussions, so this markup can help connect a forum to those answers.
Most forums do not use it. On top-1M sites running forum software, 87.6% of crawled inner pages had neither type in October 2026.
What we measured
We used four October crawls from HTTP Archive (2023 to 2026), mobile client, top-1M sites. We kept sites where HTTP Archive detects forum software and looked at the inner page it samples for each site, since threads live on inner pages. We parsed the rendered JSON-LD, flattened nested objects and @graph arrays, and flagged DiscussionForumPosting and QAPage nodes.
For 2026 we also counted which properties appear on top-level or mainEntity DiscussionForumPosting nodes. Software names are used only to show who uses the markup; property gaps are reported for all forums together.
Forum markup is still the exception
Coverage has edged up each year, while the pool of forum sites in the top 1M shrank by half.
Count
| Crawl | Forum sites | Inner pages crawled | Inner pages with forum or Q&A markup | Share % |
|---|---|---|---|---|
| Oct 2023 | 7,952 | 7,799 | 733 | 9.4 |
| Oct 2024 | 7,428 | 7,263 | 754 | 10.4 |
| Oct 2025 | 5,990 | 5,791 | 690 | 11.9 |
| Oct 2026 | 3,910 | 3,692 | 459 | 12.4 |
Source: aisearchoptimization.net analysis of 3,692 inner pages on 3,910 top-1M sites running forum software · HTTP Archive, October 2026, with trend back to 2023
Fewer forums rank in the top 1M each year. The ones that remain are slightly more likely to mark up their threads.
Who uses forum markup
Adoption by forum software, as detected by HTTP Archive. This shows where the marked-up pages come from.
| Forum software | Sites | Inner pages crawled | With forum or Q&A markup | Share % |
|---|---|---|---|---|
| XenForo | 1,604 | 1,493 | 343 | 23 |
| IPB | 564 | 498 | 61 | 12.2 |
| Discourse | 200 | 192 | 24 | 12.5 |
| phpBB | 665 | 650 | 11 | 1.7 |
| Discuz! X | 220 | 246 | 4 | 1.6 |
| vBulletin | 215 | 190 | 1 | 0.5 |
| MyBB | 125 | 119 | 1 | 0.8 |
| Simple Machines Forum | 186 | 175 | 0 | 0 |
Source: aisearchoptimization.net analysis of 3,692 inner pages on 3,910 top-1M sites running forum software · HTTP Archive, October 2026, with trend back to 2023
The crawled inner page is not always a thread, so some pages without markup are member lists, search results or category pages.
Marked-up threads often leave out the post itself
Across all forums, the basic identifiers are present but the content and replies often are not.
% of pages (N=435)
| Property | Pages | Share % |
|---|---|---|
| author | 433 | 99.5 |
| headline | 430 | 98.9 |
| datePublished | 427 | 98.2 |
| interactionStatistic | 422 | 97 |
| url | 332 | 76.3 |
| image | 237 | 54.5 |
| dateModified | 229 | 52.6 |
| text | 219 | 50.3 |
| articleBody | 157 | 36.1 |
| mainEntityOfPage | 132 | 30.3 |
| comment | 72 | 16.6 |
Source: aisearchoptimization.net analysis of 3,692 inner pages on 3,910 top-1M sites running forum software · HTTP Archive, October 2026, with trend back to 2023
Replies marked up with comment appear on just 16.6% of pages, so most markup describes the opening post and nothing more.
What this means
If your business runs a community, support forum or Q&A section, check a thread page in a schema validator. Each thread should carry DiscussionForumPosting (or QAPage for question-and-answer threads) with author, datePublished, the post text and replies as comment items. Check your forum software's settings and add-ons for structured data options before writing it by hand. An AI search optimization agency can confirm the output on a sample of threads after you switch it on.
Community threads are a source AI engines use often, and markup makes it easier to credit the right site. To see whether assistants cite your community content today, and how that affects your AI brand visibility, request a free AI visibility audit.
Limits
HTTP Archive samples one inner page per site, which may not be a thread page.
Forum detection depends on HTTP Archive's technology fingerprints; forums on custom code are not included.
We count JSON-LD only; some forum software outputs microdata, which is not counted here.
The top-1M list changes between crawls, and the drop in forum sites reflects ranking changes as well as closures.
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Cite this study
APA
Grenyo, K. (2026). 87.6% of Forum Pages Lack Discussion Markup. AI Search Optimization. https://aisearchoptimization.net/resources/data-studies/forum-discussion-markup-missing
Plain link
87.6% of Forum Pages Lack Discussion Markup - AI Search Optimization - https://aisearchoptimization.net/resources/data-studies/forum-discussion-markup-missing
Frequently asked questions
What is DiscussionForumPosting markup?
A schema.org type for forum threads and posts, with properties for author, date, text and replies. Google added support for it in late 2023.
How many forums use forum schema markup?
In October 2026, 12.4% of crawled inner pages on top-1M sites running forum software carried DiscussionForumPosting or QAPage markup, up from 9.4% in 2023.
Which forum software has the most markup?
XenForo, with 23.0% of its crawled inner pages carrying forum markup and 74.7% of all forum-marked inner pages in our sample.
What do forum markups most often leave out?
Replies and post text. Only 16.6% of DiscussionForumPosting pages mark up comments and 50.3% include text.
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